1. The Field of the Invention
This invention relates to writing instruments, and in particular concerns a writing instrument including a retraction mechanism for advancing and retracting a writing tip relative to a barrel.
2. Description of the Prior Art
In the past, retraction mechanisms have tended to be of complicated construction and therefore expensive to manufacture. Consequently, pens incorporating such mechanisms have generally been designed for the ink reservoir and writing point to be replaced when the ink supply has been exhausted. Disposable pens intended to be discarded when the ink has run out have usually been provided with a removable cap to cover the writing point during periods of non-use, but such caps are inconvenient since they are easily misplaced or lost and can become detached inadvertently. Therefore, there is a need for a retraction mechanism which is of simple construction, inexpensive to produce yet effective and convenient in operation, so that it is suitable for use in a disposable pen.